Originally Posted by No Skeez
We have done a number of swaps from the factory bag to the BI Rear Seat Bottom Bag. Unfortunately, in order to get the factory ballast hoses to work, you have to have a custom sac made with the same dimensions as the seat bottom bag, but with the valves located differently than the stock bag. The BI bag basically doubles the weight, improving the wake quite a bit. Hope this helps!
No Skeez - do you have a link to this bag?